Conventional water tanks are available which include a plurality of rows of curved panels where the panels of each row are connected end edge to end edge to form a cylindrical wall portion and where the wall portions formed by the rows are stacked and connected top edge to bottom edge to form a cylindrical wall extending from a bottom edge of the cylindrical wall mounted on a support surface to a top edge of the wall for containing water. A liner is placed over the cylindrical wall and support surface to contain the water within the tank.
Such tanks can range from relatively small scale tanks of only 6 feet in diameter and 20 feet high to much larger tanks such as 40 feet in diameter and 40 feet high.
In some cases a roof is provided and in some cases the top of the tank is merely open.
On many occasions it is necessary to access the interior of the tank for service of the liner or more typically of seals at wall penetrations where relative movement can cause breakdown in the seal and water loss.
Up to now, it has been considered highly undesirable to breach the wall and/or the liner to allow access at ground level and instead the service personnel must climb over the top edge of the wall to gain access to the interior. In all cases this requires specialized equipment. In smaller tanks this is relatively straightforward but in larger tanks the heights involved can lead to unsafe conditions or the necessity for fall restraint equipment.